zakgof / korender

3D graphics engine for Kotlin Multi-Platform

korender

Kotlin Multiplatform 3D graphics rendering engine based on OpenGL / OpenGL ES

@Composable
fun App() = Korender {
    Frame {
        Renderable(
            mesh = sphere(2.0f),
            material = standard(StandardMaterialOption.Color) {
                color = Color(0.2f, 1.0f, 0.5f + 0.5f * sin(frameInfo.time))
            },
            transform = Transform().translate(sin(frameInfo.time).y)
        )
    }
}

Supported platforms

• Desktop (Windows) - based on LWJGL
• Android - based on OpenGL ES

Features

• Rendering opaque and transparent objects
• Diffuse, specular and ambient lighting (direction light)
• Projection shadow maps with percentage close soft shadows
• Texturing:
  • uv mapped
  • triplanar
  • detail
• Bump mapping
• Custom meshes
• Wavefront .obj model file loading
• Billboards (sprites)
• Batching (instancing)
• Simple heightfield (terrain)
• Textured or shader sky
• On-screen basic GUI
• Custom shaders support
• Screen-space shaders (filters)
• Simple effects
  • smoke
  • fire
  • water

Demo app

• JVM Desktop Windows: https://github.com/zakgof/korender/releases/download/0.0.3/korender-demo-0.0.3.apk
• Android APK: https://github.com/zakgof/korender/releases/download/0.0.3/korender-demo-0.0.3.apk

Examples

Find more advanced examples

Concepts

• KorenderContext - your entry point to access engine features
• Renderable - a primitive that can be rendered. A renderable's has a Mesh (geometry) and a Material (surface properties)
• Mesh - is generally an indexed collection of vertices that form triangles. Each vertex has a set of Attributes, such as position, normal, texture coordinates, etc.
• Material - defines a renderable's surface look; consist of a Shader and its Uniforms (properties)
• Shader - compiled GPU program, consisting of vertex ang fragment shader code
• Uniforms - shader's parameters